Bertram Scharf

Northeastern University

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Georges Canévet

Laboratoire de Mécanique et d’Acoustique

Rhona P. Hellman

Northeastern University

Søren Buus

University of Copenhagen

Marie-Claire Botte

Centre National de la Recherche Scientifique

Adam Reeves

Northeastern University

Mary Florentine

Northeastern University

Bärbel Nieder

Northeastern University

Huanping Dai

University of Arizona

Andrzej Miśkiewicz

Medical University of Warsaw

Ron Peled

Tel Aviv University

Cooperative Institutions

Northeastern University

Centre National de la Recherche Scientifique

University of Illinois Urbana-Champaign

Boston University

Universidad del Noreste

Google (United States)

Technion – Israel Institute of Technology

Harvard University

New York University

Massachusetts Institute of Technology

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The role of attention in speech perception

The Journal of the Acoustical Society of America (1988)

Bertram Scharf Huanping Dai Joanne L. Miller

This study investigated the role of auditory attention during speech perception. The syllables /da/ and /ga/ were synthesized so that they differed in initial burst and third formant transition; the critical distinguishing information was in the vicinity of 2.5 Khz. Discrimination was first measured with a 1I, 2AFC procedure under six masking conditions. Performance was near chance (55% correct) when the masker was centered at 2.5 Khz, but increased as the masker moved away from this critical frequency region, reaching 100% with the masker at 1 kHz. Next examined was whether listeners' attention as they performed the task was focused specifically on the 2.5-Khz region, or spread across all frequency regions. In one condition, subjects were asked to discriminate the syllables when a weak 90-ms, 1-kHz tone was added to /da/ and, in the other condition, when a weak 90-ms, 2.5-Khz tone was added to /da/; subjects were not informed that the tones had been added. In both conditions, the masker was centered at 2.5 kHz. Performance was at 58% when the 1-Khz tone was added, but at 75% when the 2.5-kHz tone was added. In two control conditions, it was found that, when subjects were informed that the tones had been added, so that they could focus their attention on the relevant frequency regions, performance increased substantially (to 90% correct) for the 1-Khz condition, but only slightly (to 81% correct) for the 2.5-kHz condition. These results suggest that, when attempting to discriminate syllables, listeners focus their attention on the specific frequency region critical to the distinction. [Work supported by NIH.]

Tone (literature)

Psychoacoustics

Auditory feedback

10.1121/1.2025905

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Citations (5)

LOUDNESS

Elsevier eBooks (1978)

Bertram Scharf

10.1016/b978-0-12-161904-6.50013-0

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Citations (35)

SEQUENTIAL EFFECTS IN LOUDNESS

Bertram Scharf

This paper reviews the effects of one sound on the loudness of a following sound. The following sound is usually perceived as softer than when presented in isolation. At least five sequential effects can be identified. (1) Simple loudness adaptation: the earlier part of an ongoing sound results in a decline in the loudness of later parts. (2) Ipsilaterally induced adaptation: increments in the level of an ongoing sound induce a decline in the loudness of the ongoing sound. An intermittent louder sound at a nearby frequency also causes a decline in loudness. (3) Loudness recalibration: the stronger and weaker sounds of induced adaptation are separated by a silent interval, but otherwise the decline in the loudness of the weaker sound, called recalibration, seems to follow much the same rules as induced adaptation. (4) Temporary loudness shift: a very intense sound often causes a temporary decline or shift in the loudness of a following weaker sound. This temporary shift is attributed to fatigue of the cochlear hair cells. (5) Loudness enhancement: a brief sound is louder when it follows a stronger sound within 200 ms or so. These various sequential effects are largely perceptual, but their physiological bases can only be guessed at. This paper is about changes in the loudness of one sound caused by exposure to a preceding sound. With no silent interval between the two sounds and with no stimulus change, such sequential effects are generally referred to as loudness adaptation. With a silent interval, among the notable sequential effects are loudness recalibration, temporary loudness shifts, and loudness enhancement. Except for loudness enhancement, the effect of the preceding sound is either to leave unchanged or to diminish the loudness of the following sound. Fechner had little to say about loudness, no doubt because control of sound intensity was so difficult in the 19 century. He did refer to sequential effects in psychophysics with respect to the measurement of difference thresholds but not with respect to sensory magnitudes, such as loudness. Many contemporary psychophysicists (see Baird, 1997) do consider effects of preceding stimuli and responses, even of the whole context, on responses, especially in scaling procedures. I limit myself to what appear to be sequential effects on perceiving rather than uniquely or mainly on responding.

Sound change

Sound exposure

Stimulus (psychology)

Psychoacoustics

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Citations (7)

Speech reception thresholds in noise for native and non-native listeners

The Journal of the Acoustical Society of America (1984)

Mary Florentine Søren Buus Bertram Scharf Georges Canévet

The noise level at which native and non-native listeners could repeat about 50% of very simple English sentences was measured with an adaptive procedure. The 14 non-native listeners were primarily native French speaking and were 19 to 53 years old. Four native listeners were 16 to 53 years old. On each trial the listener repeated one sentence presented at 70 dB SPL via loudspeakers in an anechoic chamber. If the entire sentence was correct, the noise level was increased; otherwise it was decreased. the step size was 5 dB until the first reversal and 2 dB thereafter. The speech reception threshold, SRT, was defined as the average noise level of ten trials following the first reversal. Three SRTs were measured for each listener. All listeners could repeat eight practice sentences presented in the quiet with 100% accuracy. The average SRTs were 57 dB SPL for listeners with minimal experience in English, 62 dB SPL for listeners with moderate experience, and 68 dB SPL for listeners with extensive experience. Native listeners had an average SRT of 72 dB SPL [Work supported by the French Scientific Mission.]

QUIET

Anechoic chamber

10.1121/1.2021645

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Citations (33)

Reduction of Word-Recognition Threshold under Hypnosis

Perceptual and Motor Skills (1963)

Bertram Scharf Harold S. Zamansky

In two experiments with 24 Ss each, the recognition threshold for common English words was reduced under hypnosis. Thresholds were also reduced, however, after waking suggestions and, in one of the experiments, after a prolonged rest period. In all these cases, the amount of the threshold reduction was highly correlated with the initial threshold level. Since these initial thresholds were apparently inflated by S's expectancy for hypnosis, the subsequent threshold reduction may reflect merely the termination of this expectancy and not the direct influence of the treatment variables. The effect of hypnosis upon thresholds uninflated by the expectancy for hypnosis remains to be tested.

10.2466/pms.1963.17.2.499

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Citations (22)

Human hearing without efferent input to the cochlea

The Journal of the Acoustical Society of America (1994)

Bertram Scharf

The measurement of hearing without efferent input is possible in human patients whose vestibular nerve has been sectioned, to relieve severe vertigo usually caused by Ménière’s disease. The olivocochlear bundle, which runs in the inferior vestibular nerve, is also sectioned. Psychoacoustic measures have been made in over a dozen such patients, whose hearing levels range from normal to 40 or 50 dB. Most measurements were made only after the operation, but many were also made before. Thresholds measured before and after the operation revealed no change in the ability to detect tones either in the quiet or in noise, except when selective frequency focusing was involved. Comparisons between operated and normal ears showed a similar pattern. Other psychoacoustic tests, including measurements of intensity, frequency, and gap discrimination, of loudness functions and loudness adaptation, of lateralization, of the auditory filter (by notched noise), of overshoot, of TTS, showed either normal auditory functions or only the changes usually associated with sensorineural impairment. Besides the laboratory tests, most patients’ reports indicate no change in hearing subsequent to the vestibular neurectomy. Apparently, the one change—in selective listening—has little effect on such common auditory functions as speech perception. [Research supported by NIH.]

Psychoacoustics

10.1121/1.409698

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Citations (2)

Auditory brain stem evoked potentials: Clinical promise of increasing stimulus rate

Electroencephalography and Clinical Neurophysiology (1981)

Hillel Pratt Y Ben-David Ron Peled L Podoshin Bertram Scharf

Stimulus (psychology)

Abnormality

10.1016/0013-4694(81)91511-x

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Citations (114)

Binaural summation of loudness: Reconsidered.

Journal of Experimental Psychology (1970)

Bertram Scharf D. Fishken

10.1037/h0030159

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Citations (69)

Sensation and Measurement: Papers in Honor of S. S. Stevens

The American Journal of Psychology (1975)

Robert Sekuler Howard Moskowitz Bertram Scharf Joseph C. Stevens

I/Psychophysics, Measurement, Sensory Physiology.- Similarities of Inhibition in the Different Sense Organs.- Some Technical Notes on Psychophysical Scaling.- Relations of Peripheral Action Potentials and Cortical Evoked Potentials to the Magnitude of Sensation.- An Assessment of Ratio of Opinion Produced by Sensory-Modality Matching.- The Derivation of Stevens' Psychophysical Power Law.- Cross-Modality Matching of Money against other Continua.- The Stimulus in Information Processing.- On the Sensory Evaluation of Compliant Materials.- Ratios of Magnitude Estimates.- Measurement, Invariance, and Psychophysics.- Listen and Hear.- On the Origin of Scales of Measurement.- The New York Study of Physical Constitution and Psychotic Pattern.- Families of Converging Power Functions in Psychophysics.- On Facts and Theories in Psychophysics: Does Ekman's Law Exist?.- A Quantal Model for Psychological Magnitude and Differential Sensitivity.- A Power Function for Sensory Receptors.- II/Hearing, Speech.- Auditory Masking and Signal Detection Theory.- An Audiogram Format Conveying the Psychophysiology of Hearing.- The Human Auditory Evoked Response.- Is the Power Law Simply Related to the Driven Spike Response Rate from the Whole Auditory Nerve?.- Critical Bandwidth in Man and Some Other Species in Relation to the Traveling Wave Envelope.- Effect of Spread of Excitation on the Loudness Function at 250 Hz.- Temporal Order and Auditory Perception.- The Link Between Speech Production and Speech Perception.- Matching Loudness and Vocal Level: An Experiment Requiring No Apparatus.- Prediction of Paired-Comparison and Magnitude-Estimation Judgments of Noisiness.- Voice Spectrum and Sidetone Spectrum.- The Slope of the Loudness Function: A Puzzle.- Localization of Unlike Tones from Two Loudspeakers.- Psychophysical Correlates of Middle-Ear-Muscle Action.- Loudness and Excitation Patterns of Strongly Frequency Modulated Tones.- III/Vision, Taste, Warmth.- The Effects of Caffeine on Terminal Dark Adaptation.- Scaling of Saturation and Hue Shift: Summary of Results and Implications.- Smitty Stevens' Test of Retinex Theory.- Spatial Summation in the Warmth Sense.- Models of Additivity for Sugar Sweetness.- Visual Perceptualization of Tetrachoric Correlations.- Rod Signals in Higher Color Mechanisms: The McCollough Color Aftereffect Observed in Scotopic Illumination.- The Doubtful Phenomenon of Over-Constancy.- IV/A Brief Autobiography.- Notes for a Life Story.- S. S. Stevens' Bibliography.- Index of Names.- Index of Subjects.

Audiogram

Stimulus (psychology)

Sensation

Psychoacoustics

Psychometric function

Auditory perception

10.2307/1421905

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Citations (124)

Critical Bands and the Discrimination of Intensity Relations in Two-Tone Complexes

The Journal of the Acoustical Society of America (1966)

John F. Chaves Bertram Scharf

The intensity relations within a two-tone complex were varied by setting one tone 0.5 to 4 dB below 70 dB SPL and the other the same number of decibels above. 25 subjects, listening monaurally through earphones, tried to distinguish these complexes from complexes with both tones at 70 dB. The main variable was the frequency separation ΔF between the two tones. It was usually more difficult to detect an intensity difference within the complex when the two tones were close or far apart in frequency than when they were at some intermediate distance, roughly equal to the critical bandwidth. The effect of ΔF was clearest when the lower-frequency component was more intense than the higher-frequency component. Measures were also made with the intensity of the two components changed in the same rather than opposite directions. Here detectibility was independent of ΔF. These findings held up best at center frequencies of 1000 and 2000 cps, less well at center frequencies of 500 and 4000 cps. [Research supported by the Public Health Service, U. S. Department of Health, Education, and Welfare.]

Intensity

Tone (literature)

Center frequency

Pure tone

Decibel

10.1121/1.1942918

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Citations (2)